High speed filming or videoing of blasting patterns in opencut mining is a well established technique which, over the past fifteen years, has produced measurable and certifiable improvements in mine productivity. To date, few attempts have been made to utilize this proven technique from opencut mines, in underground mines, because of the violently destructive forces created by blasting in the confines of an underground mine tunnel, which under normal conditions would destroy any of the said high speed cameras placed in such a destructive environment.
Both the government research establishment into mining technology for the American Government in the USA, and the South African Chamber of Mines Research Establishment in Johannesburg, have conducted limited experiments into the possibility of high speed filming of underground mine blasting patterns.
These tests have been limited because of the difficulty in designing and constructing a suitable camera housing which can consistently survive the destructive forces generated during underground mine blasting at a useful distance from the blast zone. Both the American and South African tests used modified and limited (smaller than full production) blasts which were less likely to destroy the simple metal housings constructed by both research teams to protect the high speed cameras used in their attempts to film these underground blasts.
While the results obtained from these tests have proven to be of value to both the research organisations involved and the mining industries they service, the mining industry at large has not benefited significantly from these endeavours for the following reasons.
During blasting, a plume of dust shoots down the mine tunnel, blocking the view of the blast from the camera, unless the camera is placed very close to the blast, usually closer than 10 meters, so the high speed camera's vision is not blocked by the dust created during the initial round of the blast. This is one of the major problems which has defeated earlier attempts to film underground blasting patterns.
For each production mine to significantly benefit from high speed filming or videoing of blasting patterns, it must be able to high speed film or video it's own blasting patterns, in it's own mines, under it's own working conditions, geology and problems, and be able to do so at the outer extremity of the blast zone, and inside the dust plume created by the first round of the blast.
Reduced force blasting in research establishments, so that cameras will survive, cannot provide the accuracy or mass of information required for critical analysis and measurement of information specific to the problems of a particular mine operation, or positioning cameras safely away from the blast zone only allows the dust plume to obliterate camera vision.
It is the `on site` full force blast results, with the camera on the outer extremity of the blast zone, which will provide the critical information necessary for measurement and analysis of the `site specific` underground mine blasts, so research and modifications can be designed for existing practices, which ultimately will result in improved practices and eventual improved productivity, as has occurred in open cut mining as a result of the use of high speed filming techniques and analysis of the results of such high speed filming.